Collections > Electronic Theses and Dissertations > Calculation of Sensitivity Coefficients Using CMAQ-DDM for Individual Airport Emissions in the United States
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The Community Multiscale Air Quality (CMAQ) model instrumented with the Direct Decoupled Method in three dimensions (DDM-3D), an advanced method for sensitivity analysis of chemical transport models, is used to quantify individual impacts of large and mid-size US airports on ambient air quality. Sensitivity coefficients are generated for six precursor species groups, allowing estimations of ozone and PM2.5 concentrations from each of 66 individual airports. Airports were divided into groups, minimizing interference and allowing more airports to be analyzed while keeping total simulation runtimes as low as possible. Chorded aviation activity data from the Aviation Environmental Design Tool (AEDT) were used to generate speciated emissions along flight tracks during landing and takeoff (LTO) activities. Sensitivity grids were generated for ozone and primary and secondary components of fine particulate matter for the 66 airports in the domain. Emissions from these airports account for 61% of flights and 77% of fuel burn in the 2005 AEDT inventory; sensitivities from these airports account for 73% of total aviation LTO PM2.5 sensitivities and 57% of total aviation LTO ozone sensitivities in the domain. Aircraft LTO operations for all airports in the domain were found to be responsible for an increase in annual average PM2.5 concentrations of 2.4E-3 ug/m3 nationwide (0.038% of PM2.5 concentrations from all sources), with this level climbing to as high as 0.025 ug/m3 near major airports. Ozone concentrations displayed an annual domain average 8-hr max sensitivity of 1.8E-2 ppbv (0.036% of ozone concentrations from all sources). Sensitivity to PM2.5 precursor emissions from individual airports was often far-reaching. Thirteen airports produced total PM2.5 sensitivities in excess of 1E-3 ug/m3 at 250km, and 52 airports produced sensitivities in excess of 1E-4 ug/m3 at the same distance; sensitivities at these distances tend to be primarily composed of secondary species, while sensitivities closer to airports are balanced more evenly between primary and secondary species. Spatially-resolved estimation of PM2.5 from NAS-wide aircraft LTO operations was calculated to be responsible for an excess all-cause mortality of 131 (95% CI: 121--142) deaths per year. These individual airport sensitivities will be used in the future to generate further estimates of current health and economic impacts of aviation activity, and to inform policy decisions regarding growth and operations in the aviation sector.